What’s the word? Follow-ups! (and more)

We haven’t posted an update since March 25th and one volunteer pointed that out to me in a message and then asked: “What’s the word?” Well, it’s “follow-ups”… mostly.  We’re finally going to start testing live follow-ups next week. We’ll be doing the testing in the background at first and until we’re certain that it’s working properly, you won’t be able to tell that we’re doing it and the “Followups” counter on your profile will remain zero. Once we’re sure it’s working, we’ll start updating the follow-up counters and let you know anytime a follow-up gets to a certain level. Early next week, we’ll also go live with some subtle, but very important changes: We’ll improve the waterfall display processing and we’ll be adding simulated ET signals. Read on…


Being able to do follow-ups is a unique and exciting SETILive capability. If  enough users mark a signal that appears in only one waterfall diagram (and therefore a potential ET candidate), the ATA telescope can be commanded to immediately go back to collect and send us more data from that target so we see if it still looks like ET through our usual marking. If it still shows up in the same single beam, a second followup will be triggered and then basically “rinse and repeat” as long as it continues to look potentially ET. Anyone classifying signals when this happens will be getting the follow-up waterfalls for classifying as well.

When they are enabled, tested, and fully active with live notifications (hopefully next week), we expect first follow-ups to happen pretty often as you might expect since single-beam signals are not that unusual. Terrestrial signals can often appear in one beam since the amount of signal that leaks into each beam varies quite a bit and if the signal is weak, it might not be strong enough for us to see it leaking into two of the beams. The leakage can change quite a bit as the ATA adjusts its beams to track the celestial sources and as the terrestrial source (an airplane, satellite, etc. ) moves with respect to the ATA. So, if a terrestrial source happened to look ET in one set of waterfalls, it likely won’t look that way in the next set we get several minutes later when the geometry has changed between the ATA and the RFI source. So, most followups won’t go past the second level and we won’t be notifying you that a follow-up is in progress unless it survives the second set of markings. At that point you’ll know that we’re starting to track a potential ET and that will be quite exciting even though it’s very unlikely to continue to pass the following ET tests. If it does… well, now that could get very exciting.

Waterfall Changes and Simulated ET Signals

We’ll be randomly adding simulated ET signals so that we can measure our detection capabilities. As soon as you finish with a classification having an artificial signal, we’ll let you know where the signal was on the waterfall. In order to make this measurement more consistent and useful and to improve your ability to see weak signals in general, we’ll also change the waterfall processing and display to give them a more consistent brightness scale. It should improve your ability to make out very weak signals even when there’s some stronger RFI there too.

The main thing you might notice with the new waterfall processing is that the background noise pattern of random bright and dim spots will be more consistent and a bit more “filled in”. We hope this will help you pick out weak signals better and more often. It might even help reduce our tendency to see signal patterns in the noise – I’m not sure about that, though. Part of this improvement comes from keeping bright signals from causing the background to get dimmer. A side benefit is that the dark banding caused by strong signals going bright then dim should be less severe. I already know that you’ll probably see some new artifacts in the noise background that the old processing took out and we encourage you to point these and other things out in Talk as you did with the old processing, especially if it makes classification difficult. When it goes live, I’ll create a new Featured Topic on Talk for you to post any comments about these display changes and the artificial ET signals.

The statistics we collect on your classification of these artificial signals in the presence of terrestrial RFI signals will eventually become part of a peer-reviewed and published scientific paper. So, it’s important for you to continue to make your best effort at marking all signals in each waterfall as well as those that might be ET. We need to know what else was in the waterfall to properly measure our collective detection capability in the presence of a variety of RFI signals.

Thanks for your continued participation and I hope you look forward to the SETILive going to the next level with live follow-ups as much as we do.

Lou Nigra

SETILive Science Team


12 responses to “What’s the word? Follow-ups! (and more)”

  1. Daniel L says :

    Thanks for this update, things were getting a bit quiet around here and to be honest we need updates like this to keep the momentum going. I for one was starting to visit the site less than I had originally, mostly from lack of feedback and news from the SETI side of things. It can be a little tedious work without feedback, updates to the interface etc. I think the fake ET signals should keep things more interesting as it helps us gauge how accurate our marking is. I still have high hopes for this project and will continue to play my part, but please please do keep the blogs and updates regular as it really helps keep us signal markers motivated.

  2. Steve Hutchinson says :

    Hi Lou, nice to get some information, i was getting a little despondent, sorry.
    However this all sounds very exciting, I know odds seem low but with some luck?
    I would like to draw attention to a problem some (Most even all) of us are having with the system not loading, running slow etc. I have posted some times and details on ‘Talk’ ‘Bugs’ but problem is worse now than ever.

    Keep looking and listening


  3. Dale Peace says :


    Regarding Waterfall Changes above…

    Having already posed this question to Inigra in the suggestions section of Talk, a portion of it below:

    I too agree with the others that if we are looking for “weak” signals, the most likely to have traveled the vast distance across our galaxy, that the waterfall plot points should be inverted to make the weakest signals the brightest and the strongest signals the weakest. This would give us “Citizen Scientists” a great advantage in locating the weak signals being plotted along with the “normal” signal background noise.

    It’s physically impossible to simply and literally make weak signals stronger and strong signals weaker, but I assume you meant some sophisticated method of making it easier to pick out weak signals amid the noise and strong interferers. Weak signals are fundamentally and irretrievably at a comparable level to the noise as it enters the antenna. To make the signal stronger without making the noise stronger as well requires prior knowledge of the characteristics of the signal we haven’t found yet, so is impossible. However, we can experiment with the brightness and contrast scale to possibly make it easier to see against the noise background. We can make weak signals much brighter (unfortunately, the noise too) while making strong signals only a little brighter by using a non-linear brightness scale (e.g., log scale) but these will make it harder to see a weak signal crossing a strong one.

    end comments from Inigra

    I am approaching you with the same comment, but maybe with a little better explanation of what I was thinking.

    It seems to me that while the signal is being processed for the waterfall plot and the brightness assigned to each pixel, a simple algorithm could be employed to modify the brightness. For example, on a scale of 1 to 100, where 1 represents the dimmest shade and 100 represents the brightest shade, make a 100 equal a 1 in brightness, a 90 equal a 10 in brightness, an 80 equal a 20 in brightness, etc. while the waterfall plot is being processed.

    The result would be the weakest signals would be the brightest and therefore make it easier for the human mind to recognize.

    I for one, find it easier to see brighter patterns than the suspected dimmer patterns that may actually be a signal from ET.

    No matter what the outcome on this request, I will continue looking for ET on SETIlive till we find ’em.

  4. DennisG says :

    I look forward to the updates!

    You guys are located at the Chicago Planetarium right?

  5. Womanwarrior says :

    I’ve been wondering when followup would begin, and will be grateful to have the ‘continuing education’ of simulated ET signals.

  6. Mike Helms says :

    Thank you for the update Mr. Nigra. Keep the information coming our way! I am so excited to be able to participate in SETI. Thank you and the rest of the team for all the effort.

  7. Geoff Lambert says :

    I’ve been marking some things that look like spaghetti to me. Some are fairly straight and others curly-q all over the place. I mark these “broken” “erratic”. They seem like some kind of errors to me, and the majority of the samples have at least a couple of them, but many have a lot of them and I only mark a few of them. Many are nearly horizontal and many others are slanted off the perpendicular. I’m wondering if marking these types is worth it? If it is, perhaps you could adapt the marking system to allow n numver of points so that we can follow the curves (roughly).
    You can check my work to figure out what I’m referring to, I mark some other features “broken” “narrow” and these are quite different, they’re even more broken and also appear to be dead straight lines not too far off the perpendicular.

  8. frozenchosen says :

    Hi Lou: I just got home from a trip to visit Redding, California. On the way home we stopped at the Hat Creek Observatory and got a first hand look at the array. It was inspiring and encouraging, even though it was windy and cold.

    Thanks for your work. It is good to be involved in something that is truly larger than oneself.

  9. Womanwarrior says :

    I’m still waiting to hear about followup.

    It’s rather discouraging to classify signals and still see “0” in the followup box.

    (Of course, what will REALLY rock is when there’s a number other than “0” in the ET contact box!


  10. Womanwarrior says :

    I’m still waiting to hear about followup.

    It’s rather discouraging to classify signals and still see “0” in the followup box.

    (Of course, what will REALLY rock is when there’s a number other than “0” in the ET contact box!)


  11. Johna says :

    Been trying to participate but when I try to set up it says I’m not using a current version of IE even though I am. I do not want to download Chrome, that created a host of email issues for me. I’d try Safari but I have a Windows based system so don’t know if that would work? Firefox, haven’t tried it, suggestions?

  12. Lou Nigra says :

    IE doesn’t follow the new HTML standards Microsoft helped define as I understand it. It’s a common problem that sometimes can be resolved with IE settings. Do a web search for “IE compatibilitty view”. You’ve probably been this route, but the email issue might be that Chrome took over as default browser. If that’s the case, you should be able to prevent it when you install, but to be sure, close Chrome and open IE. It should ask to become your default browser (again) or you can restore it’s status in the settings somewhere. Firefox is pretty much as compatible as Chrome, but I’d guess you’d have the same email issue.

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